A BBC newsreader feared her career would be ruined if she told managers that Dave Lee Travis groped her breasts when she was live on Radio 4, a jury has heard.

Travis was a "big star" and BBC executives would have told her to "live with it" if she had complained about being sexually assaulted live on air in the early 1980s, the journalist told Southwark crown court in London.

Giving evidence from behind a white curtain in the witness box, the woman said: "If I had gone to management, I imagine it would have been: 'So what? You're a big girl, deal with it.'"

The journalist, who was a 26-year-old trainee at the time of the incident, described how Travis came up behind her and groped her breasts for the duration of a 10-second announcement as she introduced Women's Hour on Radio 4.

She is one of 11 young women who have accused the 68-year-old broadcaster of a string of indecent assaults between January 1976 and November 2008. Travis denies the charges.

The newsreader was shielded from the view of Travis as she described a feeling of "panic" and of being "frightened" that she had messed up the Radio 4 announcement because she had been molested.

Travis acted like it "was a big joke", the woman told jurors, adding that complaining would have created a "black mark" against her name because managers would not take her seriously.

"I was on probation as an announcer. There was no way I was going to start telling off this big star of Radio 1," she said. "It would probably have been a case of: 'Well, you didn't mess up the announcement so what are you complaining about?'"

She added: "Had I had the courage to go to management, who knows whether I would have been the one in trouble, the studio manager the one in trouble, or Mr Travis."

Stephen Vullo, on behalf of Travis, said the former Radio 1 DJ "denies totally" that he sexually assaulted the woman and that he had no recollection of the incident.

The journalist, who cannot be named for legal reasons, was one of two alleged victims of Travis to give evidence on the second day of his trial on Wednesday.

A young female journalist who worked alongside Travis at Chiltern FM radio station, in Buckinghamshire, said she was "paralysed with fear" during a campaign of sexual assaults that had left her female colleagues "praying it wouldn't be us".

Travis huffed and occasionally shook his head as he listened to his alleged victim, who also spoke from the witness box behind a white curtain.

The woman, who was in her late 20s at the time of the incidents between 2001 and 2002, told the court that she and her female colleagues would lower their heads at the "tell-tale sign" of Travis walking in their direction when they could smell his "strong, pungent" aftershave.

Describing three incidents that she said were seared on her memory, the woman told jurors how she screamed at Travis – calling him a "dirty old pervert" – after he pushed his hands up her skirt in the middle of the office. "He walked straight towards me. I knew what was coming. I didn't have a chance to move," she said.

"His face was inches – even less than that – from mine. He had both hands on my thighs and began rubbing my thighs. He pushed the skirt up. I could feel his fingers against my knicker elastic – at which point he tried to get his fingers under. At that point I absolutely snapped. I couldn't take it any more."

The witness said managers were "100% aware" of Travis's alleged behaviour, and that he had been banned from the newsroom after the incident that prompted her angry outburst.

Later, the former Chiltern FM employee Mark Grinnell told the jury he recalled the confrontation because Travis had been called a "dirty old man" and the comment had caused a "ripple" around the office.

A second Chiltern FM journalist later told the court that she and two female colleagues would feel "incredibly uncomfortable" whenever Travis walked into the office, describing the veteran DJ as "lechy, with his hands". She said: "Every time he came into the office he couldn't keep his hands off."